Unit dose packaging is an attractive packaging format that is used for a variety of applications. Examples of dose packaging include the well known blister package or blister card, the most common use being to contain articles such as, tablets, pills, capsules, candy and similar consumable items. Conventional blister packages generally include a blister pack that typically comprises a thermo-formed plastic sheet containing integrally formed blisters that are dimensioned to hold one or more articles. Articles are disposed within each blister and the plastic sheet is sealed to a backing sheet that normally comprises a foil, plastic film, or paperboard barrier. The backing sheet is applied to cover each blister and securely houses the articles therein, and is punctured or ruptured to release an item from a blister. Typically with paperboard barriers, gates are formed proximate to each blister to assist with removing the contents from the blister. Each gate is deformed or manipulated so that it ruptures or partially separates from the rest of the barrier, allowing the item within a blister to be pushed through the gate.
Other examples of conventional blister packages comprise a front and back paperboard sheet that are adhered together to sandwich a blister or blister pack between the two sheets. In this configuration, the blister protrudes through an aperture formed within the front sheet. The back paperboard sheet generally includes one or more gates or tear-away strips that overlay a respective one or more blisters. To access an item stored in the blister the item is typically forced through the backing sheet from the blister. While the conventional blister packages are suitable for many applications, there remain shortcomings. The conventional blister packages provide removal of the items from the blister cells, but offer no or very little child resistance. Child resistance is a feature that is particularly desired for unit dose pharmaceutical packaging, and is mandated by the Poison Prevention Packaging Act of 1970. Guidelines are prescribed for packaging to satisfy the criteria for child resistance. For example, a child resistance (CR) rating of F=1 requires that a random sampling of the subject packages not be compromised by an age specific test pool of children for a specific failure rate. This guideline is designed to ensure that the package has sufficient integrity against tampering or unauthorized access by children.
Measures taken to provide blister packages with child resistant features have generally included adding additional or thicker push-through films, applying stronger adhesion of peel films or tear-away strips, forming backings comprising heavier substrates, or adding a variety of locking mechanisms that require a combination of steps for exposing a blister. A downfall of the added safety features is that the blister package can be difficult to open by a user, is expensive and over packaged. For example, one result of added materials is that certain articles crumble when attempting to dispense the article from the reinforced backing sheet of the blister pack.
In addition to a blister package being child resistant, it is desirable that the package permit easy withdrawal of items from the package by those intended to use the item stored therein, such as an adult taking a prescription. As the blister packages are designed to be more resistant to tampering by a child, the elderly may have difficulty gaining access to the pharmaceutical dosage of medication within the package. This is especially important for users or patients whose manual dexterity and strength is reduced.
Regarding a variation of the child-resistant but senior-friendly issues presented above, clam shell packages are frequently used for many products—pharmaceutical or otherwise. An advantage of clam shell packages is that they deter on-site theft because these packages are typically constructed of relatively resistant plastics, and are thus relatively difficult to open without a sharp tool. Even a consumer who has purchased a clam shell packaged product cannot typically gain entry into the package until they have opened the package with a sharp tool. Alternatives to claim shell packages include the Natralock™ brand security package manufactured and distributed by the present Applicant. Embodiments of the Natralock™ brand package include a contiguous paperboard substrate that supports at least one item captured by a single tear-resistant layer or wrap, such as an APET bubble. Other embodiments of the Natralock™ brand package include a two-piece paperboard frame that support opposing walls of tear-resistant material, between which is captured an item. While it is typically much easier to access an item packaged in a Natralock™ brand product than a clam shell package, such access still typically is with a tool.
Accordingly, there remains in the art a need for a packaging system that is economical to manufacture and assemble, light weight, and provides child-resistant or theft-resistant security features. There also remains a need for a packaging system that permits withdrawal of the item stored therein without the use of a tool, and with little manipulation by those that purchased the item and/or are expected to use the item.